On 4/13/21 3:42 AM, Václav Kubernát wrote:
> This patch adds support for these devices:
> - YH-5151E - the PDU
> - YM-2151E - the PSU
>
> The device datasheet says that the devices support PMBus 1.2, but in my
> testing, a lot of the commands aren't supported and if they are, they
> sometimes behave strangely or inconsistently. For example, writes to the
> PAGE command requires using PEC, otherwise the write won't work and the
> page won't switch, even though, the standard says that PEC is opiotnal.
optional
> On the other hand, writes the SMBALERT don't require PEC. Because of
s/writes the/writes to/ ?
> this, the driver is mostly reverse engineered with the help of a tool
> called pmbus_peek written by David Brownell (and later adopted by my
> colleague Jan Kundrát).
>
> The device also has some sort of a timing issue when switching pages,
> which is explained further in the code.
>
> Because of this, the driver support is limited. It exposes only the
> values, that have been tested to work correctly.
>
You might want to add those details into the driver code, below the
copyright line. It would be more valuable there than in the commit log.
> Signed-off-by: Václav Kubernát <kubernat@xxxxxxxxx>
> ---
> Documentation/hwmon/fsp-3y.rst | 26 ++++
Needs to be added to index.rst.
> drivers/hwmon/pmbus/Kconfig | 10 ++
> drivers/hwmon/pmbus/Makefile | 1 +
> drivers/hwmon/pmbus/fsp-3y.c | 239 +++++++++++++++++++++++++++++++++
> 4 files changed, 276 insertions(+)
> create mode 100644 Documentation/hwmon/fsp-3y.rst
> create mode 100644 drivers/hwmon/pmbus/fsp-3y.c
>
> diff --git a/Documentation/hwmon/fsp-3y.rst b/Documentation/hwmon/fsp-3y.rst
> new file mode 100644
> index 000000000000..68a547021846
> --- /dev/null
> +++ b/Documentation/hwmon/fsp-3y.rst
> @@ -0,0 +1,26 @@
> +Kernel driver fsp3y
> +======================
> +Supported devices:
> + * 3Y POWER YH-5151E
> + * 3Y POWER YM-2151E
> +
> +Author: Václav Kubernát <kubernat@xxxxxxxxx>
> +
> +Description
> +-----------
> +This driver implements limited support for two 3Y POWER devices.
> +
> +Sysfs entries
> +-------------
> +in1_input input voltage
> +in2_input 12V output voltage
> +in3_input 5V output voltage
> +curr1_input input current
> +curr2_input 12V output current
> +curr3_input 5V output current
> +fan1_input fan rpm
> +temp1_input temperature 1
> +temp2_input temperature 2
> +temp3_input temperature 3
> +power1_input input power
> +power2_input output power
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index 03606d4298a4..9d12d446396c 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -56,6 +56,16 @@ config SENSORS_BEL_PFE
> This driver can also be built as a module. If so, the module will
> be called bel-pfe.
>
> +config SENSORS_FSP_3Y
> + tristate "FSP/3Y-Power power supplies"
> + help
> + If you say yes here you get hardware monitoring support for
> + FSP/3Y-Power hot-swap power supplies.
> + Supported models: YH-5151E, YM-2151E
> +
> + This driver can also be built as a module. If so, the module will
> + be called fsp-3y.
> +
> config SENSORS_IBM_CFFPS
> tristate "IBM Common Form Factor Power Supply"
> depends on LEDS_CLASS
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index 6a4ba0fdc1db..bfe218ad898f 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -8,6 +8,7 @@ obj-$(CONFIG_SENSORS_PMBUS) += pmbus.o
> obj-$(CONFIG_SENSORS_ADM1266) += adm1266.o
> obj-$(CONFIG_SENSORS_ADM1275) += adm1275.o
> obj-$(CONFIG_SENSORS_BEL_PFE) += bel-pfe.o
> +obj-$(CONFIG_SENSORS_FSP_3Y) += fsp-3y.o
> obj-$(CONFIG_SENSORS_IBM_CFFPS) += ibm-cffps.o
> obj-$(CONFIG_SENSORS_INSPUR_IPSPS) += inspur-ipsps.o
> obj-$(CONFIG_SENSORS_IR35221) += ir35221.o
> diff --git a/drivers/hwmon/pmbus/fsp-3y.c b/drivers/hwmon/pmbus/fsp-3y.c
> new file mode 100644
> index 000000000000..2185ab119fd2
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/fsp-3y.c
> @@ -0,0 +1,239 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Hardware monitoring driver for FSP 3Y-Power PSUs
> + *
> + * Copyright (c) 2021 Václav Kubernát, CESNET
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include "pmbus.h"
> +
> +#define YM2151_PAGE_12V_LOG 0x00
> +#define YM2151_PAGE_12V_REAL 0x00
> +#define YM2151_PAGE_5VSB_LOG 0x01
> +#define YM2151_PAGE_5VSB_REAL 0x20
> +#define YH5151E_PAGE_12V_LOG 0x00
> +#define YH5151E_PAGE_12V_REAL 0x00
> +#define YH5151E_PAGE_5V_LOG 0x01
> +#define YH5151E_PAGE_5V_REAL 0x10
> +#define YH5151E_PAGE_3V3_LOG 0x02
> +#define YH5151E_PAGE_3V3_REAL 0x11
> +
> +enum chips {
> + ym2151e,
> + yh5151e
> +};
> +
> +struct fsp3y_data {
> + struct pmbus_driver_info info;
> + int chip;
> + int page;
> +};
> +
> +#define to_fsp3y_data(x) container_of(x, struct fsp3y_data, info)
> +
> +static int page_log_to_page_real(int page_log, enum chips chip)
> +{
> + switch (chip) {
> + case ym2151e:
> + switch (page_log) {
> + case YM2151_PAGE_12V_LOG:
> + return YM2151_PAGE_12V_REAL;
> + case YM2151_PAGE_5VSB_LOG:
> + return YM2151_PAGE_5VSB_REAL;
> + }
> + return -EINVAL;
> + case yh5151e:
> + switch (page_log) {
> + case YH5151E_PAGE_12V_LOG:
> + return YH5151E_PAGE_12V_REAL;
> + case YH5151E_PAGE_5V_LOG:
> + return YH5151E_PAGE_5V_LOG;
> + case YH5151E_PAGE_3V3_LOG:
> + return YH5151E_PAGE_3V3_REAL;
> + }
> + return -EINVAL;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static int set_page(struct i2c_client *client, int page_log)
> +{
> + const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
> + struct fsp3y_data *data = to_fsp3y_data(info);
> + int rv;
> + int page_real;
> +
> + if (page_log < 0)
> + return 0;
> +
> + page_real = page_log_to_page_real(page_log, data->chip);
> + if (page_real < 0)
> + return page_real;
> +
> + if (data->page != page_real) {
> + rv = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page_real);
> + if (rv < 0)
> + return rv;
> +
> + data->page = page_real;
> +
> + /* Testing showed that the device has a timing issue. After
Somehow network subsystem multi-line alignments slipped in.
Not in hwmon, please. I cringe at those; it makes my brain focus on the
comment (because it is asynchronous) instead of the code.
> + * setting a page, it takes a while, before the device actually
> + * gives the correct values from the correct page. 20 ms was
> + * tested to be enough to not give wrong values (15 ms wasn't
> + * enough)
> + */
> + usleep_range(20000, 30000);
> + }
> +
> + return 0;
> +}
> +
> +static int fsp3y_read_byte_data(struct i2c_client *client, int page, int reg)
> +{
> + int rv;
> +
> + rv = set_page(client, page);
> + if (rv < 0)
> + return rv;
> +
> + return i2c_smbus_read_byte_data(client, reg);
> +}
> +
> +static int fsp3y_read_word_data(struct i2c_client *client, int page, int phase, int reg)
> +{
> + int rv;
> +
> + /* This masks commands which weren't tested to work correctly. Some of the masked commands
> + * return either 0xFFFF. These would probably get tagged as invalid by pmbus_core. Other
s/either// ?
> + * ones do return values, which might be useful (that is, they are not 0xFFFF), but their
s/values,/values/
> + * encoding is unknown, and so they are unsupported.
> + */
> + switch (reg) {
> + case PMBUS_READ_FAN_SPEED_1:
> + case PMBUS_READ_IIN:
> + case PMBUS_READ_IOUT:
> + case PMBUS_READ_PIN:
> + case PMBUS_READ_POUT:
> + case PMBUS_READ_TEMPERATURE_1:
> + case PMBUS_READ_TEMPERATURE_2:
> + case PMBUS_READ_TEMPERATURE_3:
> + case PMBUS_READ_VIN:
> + case PMBUS_READ_VOUT:
> + case PMBUS_STATUS_WORD:
> + break;
> + default:
> + return -ENXIO;
> + }
> +
> + rv = set_page(client, page);
> + if (rv < 0)
> + return rv;
> +
> + return i2c_smbus_read_word_data(client, reg);
> +}
> +
> +struct pmbus_driver_info fsp3y_info[] = {
> + [ym2151e] = {
> + .pages = 2,
> + .func[YM2151_PAGE_12V_LOG] =
> + PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
> + PMBUS_HAVE_PIN | PMBUS_HAVE_POUT |
> + PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 |
> + PMBUS_HAVE_VIN | PMBUS_HAVE_IIN |
> + PMBUS_HAVE_FAN12,
> + .func[YM2151_PAGE_5VSB_LOG] =
> + PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT,
> + PMBUS_HAVE_IIN,
> + .read_word_data = fsp3y_read_word_data,
> + .read_byte_data = fsp3y_read_byte_data,
> + },
> + [yh5151e] = {
> + .pages = 3,
> + .func[YH5151E_PAGE_12V_LOG] =
> + PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
> + PMBUS_HAVE_POUT |
> + PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3,
> + .func[YH5151E_PAGE_5V_LOG] =
> + PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
> + PMBUS_HAVE_POUT,
> + .func[YH5151E_PAGE_3V3_LOG] =
> + PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
> + PMBUS_HAVE_POUT,
> + .read_word_data = fsp3y_read_word_data,
> + .read_byte_data = fsp3y_read_byte_data,
> + }
> +};
> +
> +static int fsp3y_detect(struct i2c_client *client)
> +{
> + int rv;
> + u8 buf[I2C_SMBUS_BLOCK_MAX];
> +
> + rv = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
> + if (rv < 0)
> + return rv;
> +
> + if (rv == 8 && !strncmp(buf, "YM-2151E", strlen("YM-2151E")))
> + return ym2151e;
> + else if (rv == 8 && !strncmp(buf, "YH-5151E", strlen("YH-5151E")))
> + return yh5151e;
better
if (rv == 8) {
/* rest of check */
}
> +
> + dev_err(&client->dev, "Unsupported model %.*s\n", rv, buf);
Sorry I didn't notice before. This assumes that the buffer is zero-terminated,
which may not be the case. For this to work, add another byte to the buffer
(u8 buf[I2C_SMBUS_BLOCK_MAX + 1];), and add
buf[rv] = '\0';
You could actually do that before checking the returned strings and then just
use strcmp() for the model comparisons, without bothering about the return
length.
> + return -ENODEV;
> +}
> +
> +static const struct i2c_device_id fsp3y_id[] = {
> + {"ym2151e", ym2151e},
> + {"yh5151e", yh5151e}
> +};
> +
> +static int fsp3y_probe(struct i2c_client *client)
> +{
> + struct fsp3y_data *data;
> + const struct i2c_device_id *id;
> + int rv;
> +
> + data = devm_kzalloc(&client->dev, sizeof(struct fsp3y_data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + data->chip = fsp3y_detect(client);
> + if (data->chip < 0)
> + return data->chip;
> +
> + id = i2c_match_id(fsp3y_id, client);
> + if (data->chip != id->driver_data)
> + dev_warn(&client->dev, "Device mismatch: Configured %s (%d), detected %d\n", id->name, (int)id->driver_data, data->chip);
> +
> + rv = i2c_smbus_read_byte_data(client, PMBUS_PAGE);
> + if (rv < 0)
> + return rv;
> + data->page = rv;
> +
> + data->info = fsp3y_info[data->chip];
> +
> + return pmbus_do_probe(client, &data->info);
> +}
> +
> +MODULE_DEVICE_TABLE(i2c, pmbus_id);
> +
> +/* This is the driver that will be inserted */
Nit: Useless comment
> +static struct i2c_driver fsp3y_driver = {
> + .driver = {
> + .name = "fsp3y",
> + },
> + .probe_new = fsp3y_probe,
> + .id_table = fsp3y_id
> +};
> +
> +module_i2c_driver(fsp3y_driver);
> +
> +MODULE_AUTHOR("Václav Kubernát");
> +MODULE_DESCRIPTION("PMBus driver for FSP/3Y-Power power supplies");
> +MODULE_LICENSE("GPL");
>
